Lithium is an alkali metal, and like all the other alkali metals, it reacts spontaneously with water, liberating hydrogen gas. The farther down you go in the periodic table, the more reactive the alkali metals become, and as the uppermost one lithium is the least reactive. But it's still a fairly vigorous reaction, and lithium can catch fire spontaneously on a humid day. Lithium is amazingly light, only half the density of water. It would be a great metal for making airplanes out of if it weren't so soft and didn't explode on rainy days. Instead it's used in high-quality batteries and as a medication for mood disorders, because dissolved as lithium ions, it moderates nerve impulses in a way that, for poorly understood reasons, moderates mood swings (see the pills below for more on this).

Long-life AA battery.
Initially only used in fancy camera batteries, lithium is now available in AA and 9V batteries for use in things like smoke detectors and digital cameras. They are more expensive than regular batteries, but last a lot longer which makes the cost per unit of energy competitive. They also have a very long shelf life compared to other batteries so they do well in emergency flashlights and the like.Source:Radio ShackContributor:Theodore GrayAcquired:7 August, 2002Price: $3Size: 2"Purity: <5%

Lithium oxide crystals.
If you had some thin lithium foil what would you do with it? I thought that maybe I could melt it into a lump, if I bathed the crucible in helium from a small balloon-filling tank (to prevent rapid oxidation) as I heated it from below. I was wrong.
Even with the helium shield gas, the lithium ignited almost immediately, and then proceeded to burn in much the same way lump magnesium does, only much faster (especially after I turned off the helium). This probably means I wasn't getting enough helium around the crucible, and some moist air was working its way in. Or maybe my helium, which just came from a disposable balloon filling tank, contained an oxygen impurity, which is not at all unlikely. Another possibility is that there was chemical contamination from the battery that permitted combustion.
(After seeing this, reader Walt Zarnoch sent the following: "I just read your page about melting lithium. You jarred my memory when you were talking about the possibility of oxygen impurities in the gas. I have heard that some of the suppliers of helium intended for store kits actually add oxygen intentionally, in small quantity, to the gas so that kids like me don't suffocate when inhaling helium from a balloon." So, that explains that. These days I have a large tank of argon for these purposes.)

I decided to change plans and just let a bigger piece of it (folded up tightly into a lump) burn itself out in the crucible. It lit instantly with a propane torch and burned quite dramatically, and very, very hotly. It actually cracked the tiny thimble-sized ceramic crucible I had it in. (Mind you, this is (was) a high-temperature ceramic crucible intended for burning and melting things in. It's not supposed to crack just because you make it hot.)

The explanation for this was kindly provided by reader Yehoshua Sivan from Israel, who wrote as follows:

About 27 years ago I thought I would melt lithium in a ceramic crucible, and then suck it up into a glass tube (using a propipet, not my mouth!), to preserve a specimen, as I had already done with sodium and potassium [incidentally the specimens prepared then are as shiny today as when prepared originally; the oxide at the open ends of the tube acts as a plug preventing further oxidation, and the tube is kept in paraffin oil anyway]. Well, the lithium ignited, I beat a hasty retreat and watched the reaction through the crack in the door, and after some kind of explosion a piece of burning lithium fell on the brand new asbestos table (yes, they were still fitting asbestos tables then), where it also exploded, leaving a hole in the surface. I subsequently explained to my colleagues that now the table really looked as if it belonged to a chemistry laboratory.

I thought then, and I see no reason to think otherwise now, that this was a simple oxidation-reduction reaction, in which the lithium "steals" the oxygen from the silicon dioxide and other oxides in the ceramic (and in the asbestos). The reaction is analogous to the well known magnesium-sand reaction, or to the formation of a black silicon mark on test-tubes in which Mg or Na has been burned (e.g. in the classic magnesium burning in steam reaction, or when I burn sodium in a flow of chlorine).

Sounds very familiar. This being a small world, I suppose it should come as no surprise to anyone that Yehoshua has been proof-reading the Hebrew translation of Uncle Tungsten, whose author Oliver Sacks recently came to visit me, and that Sacks' mother was Yehoshua's mother's family doctor. Nope, doesn't surprise me at all.

Yehoshua also pointed out two interesting articles about the great lithium fire of 1998, which occurred at a chemical waste dump in Israel: Article 1, article 2.

Lumps.
The irritating thing about storing lithium is that it floats on the oil. That means unless you completely fill the jar, there's always a bit poking out above the oil, and that part starts oxidizing. The effect of which you can clearly see in the picture of this sample.

Click the source link for an interesting story about where this sample came from.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.

Pills for mood disorders.
Lithium, just plain lithium (as a salt), has been used for decades as a treatment for manic-depressive disorders and other illnesses that effect the affect. There aren't very many elements that are used as medical treatments (other than as nutritional supplements like iron and calcium). Two examples, with links to articles about their uses, are carbon (legitimate) and phosphorus (historical). Although the pills actually contain a lithium salt (lithium carbonate), it is the simple lithium that does the work. One theory is that because it is in the same column in the periodic table as sodium and potassium (all are alkali metals), it is able to stand in for them in their important role in the transmission of nerve impulses. By modifying in some poorly understood way how nerve signals propagate, lithium just happens to calm mood swings.

An element is certainly a rather blunt instrument compared to, say, a carefully crafted organic molecule, but if it does the job, who's to complain?

The source of this sample, Raph Levien, is as fascinated as I am by the fact that plain lithium is still a popular mood-stabilizing medication. A family member of his switched from lithium to a different medication around the same time he discovered my Periodic Table, so naturally he thought of contributing the leftover pills to the table. (There's a lesson here for anyone reading this who has a spare element handy....)

I was a bit surprised at how many pills he sent, especially after reading that as few as 20 can be fatal. (The toxic dose is very close to the therapeutic dose, and since these pills are given to people who are, well, depressed, you can imagine that some care has to be take to avoid suicide attempts!) I've sealed a sub-lethal dose in a plastic display container and locked the rest up for safekeeping.

The purity (weight-percent lithium) of the sample was easy to calculate (especially after Yehoshua Sivan pointed out the error in my first attempt). The pills weigh 0.4163g each and are clearly labeled as containing 300mg (0.3g) of lithium carbonate (Li2CO3) each. Multiply this ratio by the ratio of twice the atomic weight of lithium to the molecular weight of lithium carbonate and you learn that the pills are about 13.6% elemental lithium.

Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

Pacemaker batteries.
These batteries are designed to be implanted in patients to power their cardiac pacemakers. The seller reports they are from the liquidation of a biomedical products company and had an original list price of $500 each. Jeez, for that price I'll slice my own chest open and drop in a couple of Duracells. They are probably single-use lithium batteries, but maybe they are lithium-ion rechargeable, I'm not sure. No, I won't sell you one for your pacemaker.
Note that these are, from a safety point of view, probably superior to the one I have listed under plutonium.Source:eBay seller heruurContributor:Theodore GrayAcquired:30 December, 2003Text Updated:11 March, 2007Price: $14.50Size: 2.5"Purity: <5%Sample Group:Medical

Puffed-up laptop battery.
Defective lithium laptop battery that puffed up to twice its normal thickness. Here you can see a second one taken out of its outer casing:

Vacuum packed slug.
This is an amazing rough cylinder of lithium metal. Amazing because it's so incredibly light. It seems to weigh almost nothing, especially if you pick it up knowing it's made of solid metal, which it is. The density of lithium is half that of water, far lighter than anything you normally think of as a light metal (magnesium, beryllium, aluminum, titanium, all these are three to nine times denser than lithium).
It's vacuum packed in plastic to prevent it from rapidly turning into lithium oxide dust: It's not stable in air, and even in this packaging it's not going to last long: You can already see spots of oxidation forming on the surface as air and water diffuse through the plastic. This is of course one reason why people don't make things out of lithium: They wouldn't last long. The other reason is that it's quite soft, useless as a structural metal.Source:Juan JimenezContributor:Juan JimenezAcquired:11 August, 2007Text Updated:11 August, 2007Price: DonatedSize: 3"Purity: >99%

Mica sheet.
This is a sheet of mica, a papery thin mineral that was often used as an electrical insulator. The term mica refers to a range of specific minerals and I don't know which one this is exactly, so the composition is just a guess.Source:Mark PetersonContributor:Mark PetersonAcquired:13 January, 2010Text Updated:13 January, 2010Price: DonatedSize: 3"Composition: (KLi2Al(Al,Si)3O10(F,OH)2